Inclusion body myositis.

[inclusion body myositis]

The idiopathic inflammatory myopathies (IIMs ) are a heterogeneous group of rare disorders that share many similarities . In addition to sporadic inclusion body myositis (IBM ), these include dermatomyositis , polymyositis , and autoimmune necrotizing myopathy . IBM is the most common IIM after age 50 years . Muscle histopathology shows endomysial inflammatory exudates surrounding and invading nonnecrotic muscle fibers often accompanied by rimmed vacuoles and protein deposits . It is likely that IBM is has a prominent degenerative component . This article reviews the evolution of knowledge in IBM , with emphasis on recent developments in the field , and discusses ongoing clinical trials .